Can a Car Misfire Fix Itself? A Christmas Miracle or Something More?
Experiencing a rough-running engine in your vehicle can be concerning, especially when the check engine light illuminates. For one owner of a 2014 T&C with around 63,000 miles, this became a reality. It began with a noticeable roughness in the engine’s performance, culminating in the dreaded check engine light appearing on November 28th, signaling a misfire in cylinder 3. This immediately raises the question many car owners ponder: Can A Car Misfire Fix Itself?
Initially, a trip to a trusted mechanic seemed to resolve the issue. Upon inspection, a surprising discovery was made – a rodent nest nestled under the intake manifold, despite the vehicle being driven frequently. Further investigation revealed a defective ignition coil on cylinder #3. As a preventative measure, and considering the labor involved, the mechanic recommended replacing all spark plugs. Following the removal of the rodent debris, replacement of the intake manifold and gasket set, the faulty ignition coil, and the spark plugs, the error code was cleared. While the mechanic reported improved driving, the owner still sensed a slight roughness, initially dismissing it as paranoia.
However, the relief was short-lived. The very next day, with the family loaded and ready to go, the check engine light reappeared. A subsequent visit to the mechanic led to a recommendation to take the vehicle to the dealership, suspecting a potential recall. Unfortunately, the recall for ignition coil issues was only applicable to older models (2013 and earlier) and specific cylinders (2, 4, and 6), not cylinder 3 on a 2014 model.
The dealership’s diagnosis painted a more concerning picture. After swapping ignition coils and confirming the misfire persisted on cylinder 3, they conducted further tests. An injector OHM test passed, but a compression test revealed intermittent compression in cylinder 3. The dealership’s assessment pointed towards potential valve issues – intermittent intake valve closure, causing pressure to escape back through the intake manifold. Their recommendation: a cylinder head replacement, which the customer, understandably, declined at that moment.
This is where the story takes an unexpected turn. For the next two weeks, the van was driven locally while the owners deliberated on whether to repair the engine or replace the vehicle altogether. Then, on Christmas Eve, en route to the airport, a surprising event occurred – the van started running noticeably better, and miraculously, the check engine light switched off.
As of January 30th, weeks later, the van continues to run smoothly, and the check engine light remains off. This raises the perplexing question: was it truly a “Christmas miracle,” or is there a more logical explanation for a misfire seemingly resolving itself? Could debris have been temporarily lodged in the valve area and then cleared itself? Or is there a more ominous possibility – something now lodged in a position that masks the problem, only to resurface later with potentially more severe consequences?
Several theories could explain this intermittent misfire and its apparent self-correction. Sometimes, a minor issue like carbon buildup on valves or a small piece of debris interfering with valve seating can cause a temporary misfire. It’s possible that with continued engine operation and heat cycles, this debris dislodged itself, or carbon deposits burned off, leading to improved valve function and the cessation of the misfire. Intermittent electrical issues could also cause temporary misfires if a loose connection or sensor malfunctioned briefly and then corrected itself.
However, it’s crucial to acknowledge that while the misfire seems to have disappeared, underlying issues might still exist. Intermittent problems can be notoriously difficult to diagnose, and a misfire caused by valve issues, even if temporarily resolved, could return. Therefore, while it may seem like a Christmas miracle, it’s advisable to remain vigilant. Continued monitoring of the engine’s performance and potentially a follow-up inspection to thoroughly assess the valve train could provide peace of mind and prevent potential future problems. While a car misfire can sometimes appear to fix itself due to minor, temporary issues, it’s essential to rule out more serious underlying causes to ensure long-term engine health and reliability.
